class_docstr: test layout templates
docstr: test creating with default values
docstr_tok: ["test","creating","with","default","values"]
code: def test_create_with_defaults(self):
      "test creating with default values"
  
      footer = widgets.Button()
      header = widgets.Button()
      center = widgets.Button()
      left_sidebar = widgets.Button()
      right_sidebar = widgets.Button()
  
      box = widgets.AppLayout(
          footer=footer,
          header=header,
          center=center,
          left_sidebar=left_sidebar,
          right_sidebar=right_sidebar,
      )
  
      assert box.layout.grid_template_areas == (
          '"header header header"\n'
          + '"left-sidebar center right-sidebar"\n'
          + '"footer footer footer"'
      )
      assert box.footer.layout.grid_area == "footer"
      assert box.header.layout.grid_area == "header"
      assert box.center.layout.grid_area == "center"
      assert box.left_sidebar.layout.grid_area == "left-sidebar"
      assert box.right_sidebar.layout.grid_area == "right-sidebar"
  
      assert len(box.get_state()["children"]) == 5
  
      # empty layout should produce no effects
  
      box = widgets.AppLayout()
      assert box.layout.grid_template_areas is None
      assert box.layout.grid_template_columns is None
      assert box.layout.grid_template_rows is None
      assert len(box.get_state()["children"]) == 0
  
imports: from unittest import TestCase
  from unittest import mock
  import pytest
  import traitlets
  import ipywidgets
  from ipywidgets.widgets.widget_templates import LayoutProperties
label_desc: Use image node_id 1 for calling the TestAppLayout obj's underlying member method code with example usage: obj.test_create_with_defaults() without return types